anchor property
The relative position of the zero scroll offset.
For example, if anchor
is 0.5 and the AxisDirection determined by
scrollDirection
and reverse
is AxisDirection.down or
AxisDirection.up, then the zero scroll offset is vertically centered
within the viewport. If the anchor
is 1.0, and the axis direction is
AxisDirection.right, then the zero scroll offset is on the left edge of
the viewport.
Most scroll views by default are ordered GrowthDirection.forward.
Changing the default values of ScrollView.anchor
,
ScrollView.center
, or both, can configure a scroll view for
GrowthDirection.reverse.
{@tool dartpad}
This sample shows a CustomScrollView
, with Radio buttons in the
AppBar.bottom that change the AxisDirection to illustrate different
configurations. The CustomScrollView.anchor
and CustomScrollView.center
properties are also set to have the 0 scroll offset positioned in the middle
of the viewport, with GrowthDirection.forward and GrowthDirection.reverse
illustrated on either side. The sliver that shares the
CustomScrollView.center
key is positioned at the CustomScrollView.anchor
.
** See code in examples/api/lib/rendering/growth_direction/growth_direction.0.dart ** {@end-tool}
Implementation
final double anchor;